Stop mechanism for spur-gearing.



' N0. 660,35l. Patented Oct; 23, 1900 W. l. WHITEHURST. STOP MECHANISM FOR SPUR HEARING.

(Application filed June 80, 1900.)

(No Model.)

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UNITED STATES PATENT OFFICE.

WALTER I. \VHITEHURST, OF BALTIMORE, MARYLAND.

STOP MECHANISM FOR SPUR-GEARING.

SPECIFICATION forming part of Letters Patent N 0. 660,351, dated October 23, 1900.

Application filed June 30, 1900. Serial No. 221110. (No model.)

To all whom, it may concern:

Be it known that I, WALTER I. WHITE- HURST, of the city of Baltimore, in the State of Maryland, have invented certain Improvements in Stop Mechanism for Spur-Gearing, of which the following is a specification.

This invention relates to certain improvements in spur-gearing in which a constantlyrotating driver is required to intermittently transmit to the driven wheel a complete or partial rotation; and itconsistsin the employment of a mutilated driverthat is to say, a gear-wheel having portions of its circumference devoid of teetha complete driven wheel, and stop mechanism whereby the driven gear-wheel is held immovable during the period or periods that the teeth of the driver are inoperative by being out of mesh with the teeth of the driven wheel, as will hereinafter fully appear.

In the further description of the said invention which follows reference is made to the accompanying drawings, forming a part hereof, and in which Figure l is a face view of a mutilated-driver gear-wheel, a complete driven gear-wheel, and the stop mechanism which holds the driven wheel while the driver is inoperative to transmit rotation. Fig. 2 is an edge view of the driver gear-wheel looking in the direction indicated by the straight arrow in full lines. Fig. 3 is an edge view of the driven gear-wheel looking in the direction indicated by the straight arrow in broken lines.

Referring now to the drawings, A represents a mutilated spur gear-wheel which constitutes the driver, and B a perfect or complete spur-pinion which is driven by the mutilated wheel A. The pitch diameters of the two wheels are respectively as two is to one. The shafts of the driver and the driven wheels are denoted by a and b. \Vith the diameters of the wheels in the proportions stated it is required that the driven wheel B shall make two half-rotations for each complete rotation of the driver, and between each of the semirotations of the driven wheel it (thedriven wheel) shall stop for a period equal to that 00- cupied in performing a half-rotation. To effect this result, the driver A is provided with teeth on two diametrically-opposite quarters of its circumference, the intervening spaces or segments being smooth or devoid of teeth.

On the end of the driver A and projecting beyond the plain segments of the rim are segmental flanges G and D, which in length occupy the entire distances between the toothed segments.

The driven gear-wheel B is provided with a full set of teeth and two segmental flanges E and F, which project from its end and are situated diametrically opposite each other. These flanges are adapted to fit against the smooth segments of the driver, as shown in Fig. 1, and their office is to hold the driven wheel when its teeth are not in mesh with those of the driver, as hereinafter explained.

Supposing the driver and driven gearwheels to be in the relative positions shown in the drawings and the driver to be in rotation in the direction indicated by the curved arrow in full lines, the driven wheel is held and cannot rotate; but as soon as the end 0 of the segmental flange D reaches the center of the flange E the driven wheel is free to rorate in the direction indicated by the curved arrow in broken lines, and rotation begins as soon as the tooth d of the driver comes into mesh with the teeth of the driven wheel, operative contact being effected coincident with the release of the flange E. The rotation of the driven wheel, begun as described, continues until the last tooth of the upper series of teeth of the driver leaves the teeth of the driven wheel. At this timethe flange F has reached the position at first occupied by the one E and further rotation of the driven.

wheel consequent upon momentum pre vented. A second semirotation of the driven wheel begins when the tooth g comes into mesh with the teeth of the driven wheel, and the operation as described is repeated.

I have described the gearing as arranged to effect two semirotations of the driven wheel to each complete rotation of the driver; but it is evident that a great variety of different results may be produced by Varying the relative diameters of the two wheels and the relative lengths of the toothed and plain segments of the driven wheel, and I therefore do not restrict my invention to the use of a driver and a driven Wheel of the relative proportions described.

I claim as my invention- In combination With a mutilated gearwheel having a flange projecting laterally from its end, and which in position is coincident with that portion of rim of said Wheel which is devoid of teeth, a full-toothed gear- Wheel driven from the first Wheel and having 1 

